The invention relates to a torsional vibration damper for damping out vibrations and rotational fluctuations in a shaft which is driven by the intermittent application of a discontinuous force, such as the crankshaft of an internal combustion engine.
The vibrational problems inherent in internal combustion engines and in other applications wherein a shaft is driveably rotated by the intermittent application of a discontinuous torque-like force have been recognized for some time. Vibrational dampers and torsional balancers have been designed to control vibrations and prevent the oscilations from building up to the point that the engine or other parts of the vehicle may be damaged or to the point where the operator feels uncomfortable.
The vibrational dampers previously used were generally crude, expensive to make, and difficult to repair. Such dampers usually employed many parts and were extremely difficult to assemble. Some used shock-absorbing inserts which had to be individually installed at a plurality of locations on a fly wheel-type mass. Others utilized concentric layers of shock-absorbing materials such as rubber or the like sandwiched between annular concentric layers of metal. These dampers proved to be very difficult to make and have proved too expensive to attain widespread acceptance in the industry.
This invention presents a method and apparatus for solving the torsional vibration problem in a relatively inexpensive manner. A spiral slotted disk is formed as an integral unit by metal casting techniques and the disk in then attached to the shaft to dampen out the vibrations.